Sliding coating for winter sports equipment

ABSTRACT

According to the invention, a sliding coating for winter sports equipment which is a blend of a copolymer (I) and a copolymer (II) is provided, the copolymer (I) being a propylene copolymer which contains at least 50% of structural building blocks which originate from propylene monomers, and the copolymer (II) being an ethylene copolymer which has at least 50% of structural building blocks which originate from ethylene monomers.

This application claims priority to German Patent Application No. 103 05088.4 filed Feb. 7, 2003, the contents of which are incorporated byreference herein in its entirety.

The invention relates to a sliding coating for winter sports equipment,in particular for skis and snowboards. The sliding coating may beextruded from a polymer material in a simple manner. The inventionfurthermore relates to the winter sports equipment coated with thesliding coating.

The quality of winter sports equipment intended for sliding, for exampleon snow, in particular of skis and of snowboards, is determined to alarge extent by their sliding properties. Such winter sports equipmenttherefore has as a rule a sliding coating which is intended to improvethe sliding properties of the equipment on snow. Such a sliding coatingsubstantially comprises a sheet which is adhesively bonded to the skisor the snowboards with the aid of suitable adhesives. Such a slidingcoating should be as hydrophobic as possible in order to ensure goodsliding.

Owing to its outstanding sliding properties over a very broad spectrumof different types of snow, high density polyethylene was initially usedas material for the sliding coating (CH-A 601394) but has problems withrespect to the mechanical strength and the resistance to wear. Theseproblems are solved by using ultra-high molecular weight polyethylene(UHMW-PE), but coatings of UHMW-PE cannot be produced by extrusion buthave to be produced by a complicated procedure, for example by pressing,sintering and subsequent peeling (CH-A 601394).

A number of proposals has been made for solving these problems andimproving the sliding coatings, for example by using a crosslinkedpolyethylene-based polymer obtainable by extrusion (CH-A 601394) or byincluding water-soluble compounds in the sliding coating (CH-A 601392).A more recent development proposes a sliding coating comprisingpolytetrafluoroethylene (AT-B 394 951), which, however, is not veryadvantageous simply for cost reasons and moreover does not sufficientlysolve the problems of the sliding coatings for winter sports equipment.None of these proposals have become established in practice, and modernskis and snowboards have, as a rule, a sliding coating comprisingUHMW-PE, which, owing to the high crystallinity, has the highestmechanical and chemical stability of the polyethylenes. Thispolyethylene was originally used in medical technology for theproduction of hip joints and is processed in powder form likethermosetting plastics with the use of customary antistatic agents andlubricants in pressing and sintering processes.

Other polyolefins, such as polypropylene, have to date been regarded asbeing unsuitable for sliding coatings for winter sports equipment sincethey do not have advantageous sliding properties.

It is also known that the sliding properties of sliding coatings can beimproved by applying a surface structure which further improves thehydrophobic properties of the coating. One difficulty, however, is thatthe effect of the surface structure no longer occurs when the structureis damaged, for example by slight mechanical influences in the course ofuse.

The slidability of skis is also improved by the use of special waxes,which is usually also required in the case of skis provided with asliding coating. The reason for the use of waxes is firstly that theyimprove the hydrophobic properties of the sliding coating and secondlythat polyethylene, like virtually all plastics, shows virtually nochange in its surface hardness in a temperature range from about +20 to−20° C., whereas the sliding properties of the snow change as a functionof temperature. Accordingly, waxes which, through a very wide range ofadditives, are designed for the various temperatures and types of snoware used, a harder surface being desired at lower snow temperatures anda softer surface at higher snow temperatures. In addition, waxes which,in addition to adjustment of the surface hardness, also formnanostructures which give rise to a lotus effect and hence ensure acompletely unwettable surface are also obtainable. However, the use ofwaxes is complicated and a correct choice of a wax is difficult. Inpractice, it is necessary to stock a plurality of waxes in order to beable to react appropriately to different snow conditions.

There is however a demand for a better sliding coating for winter sportsequipment, which sliding coating can be easily produced and has improvedproperties, in particular sliding properties, compared with the known,polyethylene-based coatings. In particular, there is a demand for acoating with which it is possible to achieve sliding properties whichare otherwise possible only by using special waxes, so that it ispossible substantially or completely to dispense with the use of waxes.The winter sports equipment should be capable of being producedeconomically.

According to the invention, a sliding coating for winter sportsequipment is provided, which sliding coating comprises a special blendof two copolymers which are designated below as copolymer (I) and ascopolymer (II). The invention also relates to winter sports equipment,in particular skis, which are equipped with such a sliding coating.

Copolymer (I) is a copolymer of propylene and at least one furtherolefin which comprises at least 50% of structural building blocks whichoriginate from propylene monomers, based on the total number ofstructural building blocks. As a rule, however, these structuralbuilding blocks account for not more than 99% of the copolymer, based onthe total number of structural building blocks. The copolymer (I)preferably comprises 70 to 99%, more preferably 75 to 98%, in particular80 to 95%, for example about 90%, of structural building blocks whichoriginate from propylene monomers (based in each case on the totalnumber of structural building blocks).

The copolymer (I) moreover also contains structural building blockswhich originate from at least one further olefin, preferably fromethylene. The proportion of the further olefin (of the further olefins)accounts for the remainder of the copolymer (I) (to 100% of thestructural building blocks), so that the copolymer (I) is preferably apropylene/ethylene copolymer whose content of structural building blockscomprising propylene is as defined above and in which the structuralbuilding blocks originating from ethylene account in each case for theremainder of the copolymer. Instead of a pure propylene/ethylenecopolymer, an ethylene/propylene-diene terpolymer (EPDM) which may alsocontain dienes, such as cyclooctadiene, dicyclopentadiene and/orhexadiene, in addition to propylene and ethylene can preferably also beused. It is also possible for higher olefins or dienes to be present inthe copolymer. In this case, too, the proportion of structural buildingblocks in the copolymer (I) which originate from propylene is asdescribed above, while the structural building blocks of the copolymerwhich originate from ethylene or other olefins or from the diene ordienes account for the remainder.

The copolymers (I) which are most preferred according to the inventionare commercially available, for example from Exxon Mobil under the namePP 7011L1.

The copolymer (I) preferably accounts for 10 to 99% by weight, morepreferably 10 to 90% by weight, in particular 50 to 90% by weight, e.g.50 to 80% by weight or 60 to 80% by weight, e.g. about 80% by weight orabout 70% by weight, of the blend of the copolymers (I) and (II).

The second substantial component in the copolymer blend is the copolymer(II), which is a copolymer of ethylene and at least one further olefinwhich contains at least 50% of structural building blocks whichoriginate from ethylene (based on the total number of structuralbuilding blocks). The copolymer (II) contains, as a rule, not more than99% of structural building blocks which originate from ethylene and inparticular has 70 to 99% of structural building blocks originating fromethylene, more preferably 75 to 98%, in particular 80 to 95%, forexample about 90%, based in each case on the total number of structuralbuilding blocks. The copolymer (II) moreover contains structuralbuilding blocks which originate from at least one further olefin,preferably from an olefin having 4 to 10 carbon atoms, in particular 6to 10 carbon atoms, most preferably from octene.

According to the invention, it is likewise preferred if the copolymer(II) also contains building blocks which originate from a diene or aplurality of dienes, as are known from the EPDM rubbers. In any case,the proportion of building blocks which originate from ethylene is asdefined above, while the remaining building blocks originating fromfurther olefins or dienes account for the remainder of the copolymer(II). The preferred copolymers (II) which can be used according to theinvention are commercially available, for example from Dexplatomer underthe name Exact 0203 or Exact Octene-1 Plastomer.

The copolymer (II) preferably accounts for 1 to 90% by weight, morepreferably 10 to 90% by weight, in particular 10 to 50% by weight, e.g.20 to 50% by weight or 20 to 40% by weight, for example about 20% byweight or about 30% by weight, of the blend of the copolymers (I) and(II).

Preferably, both the copolymer (I) and the copolymer (II) are randomcopolymers. The term “copolymers” as used in the context of thisdescription includes not only copolymers comprising two monomer unitsbut also copolymers which are composed of more than two differentmonomer units, in particular of three different monomer units or fourdifferent monomer units. The term “copolymers” as used here thereforealso includes in particular terpolymers. The term “olefin” as used hereincludes compounds having one or more double bonds, preferably havingone or two double bonds (dienes), which preferably contain not more than16, more preferably not more than 10, carbon atoms and which may bebranched or straight-chain.

Advantageously, the copolymer blend for the production of the slidingcoating according to the invention also contains a lubricant known perse and suitable for polypropylenes. If the lubricant is present, it ispreferably present in an amount of 0.1 to 30% by weight or of 5 to 30%by weight, more preferably in an amount of 0.5 to 10% by weight or of 1to 10% by weight, for example in an amount of about 1% by weight or ofabout 3% by weight, based on the total weight of the blend of copolymer(I) and copolymer (II). Particularly preferably, the lubricant is acustomary hydrophobic lubricant, for example based on primary orsecondary fatty acids stable at high temperatures, such as primary fattyacid amines, or is a carboxylic ester. A mixture of a lubricant based onprimary fatty acids stable at high temperatures with one or morecarboxylic esters is also particularly preferred. Customary commercialproducts are the products Hecoslip 130 PO and Hecoslip 114 PP fromHecoplast GmbH (Iserlohn, Germany). A mixture of a primary fatty acidstable at high temperatures and a carboxylic ester in a ratio of about1:2 is particularly preferably used.

The copolymer blends for the production of the sliding coatingsaccording to the invention may furthermore contain customary antistaticagents, in particular the antistatic additives known for polypropylene,such as carboxylic esters. Such antistatic agents, if they are present,are preferably present in an amount of 0.1 to 30% by weight or 5 to 30%by weight, more preferably of 0.5 to 10% by weight, for example in anamount of about 1% by weight, based on the total weight of the blend ofcopolymer (I) and copolymer (II).

Furthermore, the copolymer blends for the production of sliding coatingsaccording to the invention may also comprise customary nucleatingagents, in particular nucleating agents customary for polypropylene.Nucleating agents are nucleus formers, such as sodium benzoate, whichwere first introduced in the 60 s and which are obtainable, for example,from Henkel KGaA (Düsseldorf, Germany) or from Hecoplast GmbH (Iserlohn,Germany). According to the invention, organic nucleating agents, such assugar-based nucleating agents, such as sorbitol acetals, are preferred.A referred commercial product is the product Heconuk 484PP fromHecoplast. Such nucleating agents, if they are present, are preferablypresent in an amount of 0.1 to 30% by weight, more preferably of 0.5 to10% by weight, for example in an amount of about 2% by weight, based onthe weight of the copolymer (I).

In a preferred embodiment of the invention, the copolymer blends for theproduction of the sliding coatings according to the invention containboth at least one nucleating agent as defined above and at least onelubricant as defined above, in each case in the above-mentionedpreferred amounts. It is also preferred if the lubricant is partly orcompletely bound to the nucleating agent. If a nucleating agent ispresent, primary fatty acids and/or secondary fatty acids are preferablyused as the lubricant, preferably in a proportion of 1 to 90% by weight,based on the total weight of the nucleating agent, more preferably in aproportion of 1 to 10% by weight, based on the total weight of thenucleating agent, in particular in a proportion of about 7% by weight,based on the total weight of the nucleating agent.

In the preferred embodiment, in which the preferred copolymer blendcontains both a nucleating agent and a lubricant which is optionally or(preferably) partially bound to the nucleating agent, the lubricant usedis particularly preferably a mixture of a primary fatty acid stable athigh temperatures and a carboxylic ester in a ratio of about 1:10.

Further customary additives may also be present in the copolymer blendfor the production of the sliding coatings according to the invention,such as additives for improving the hydrophobic and antistaticproperties or the resistance to weathering and the scratch resistance,it being possible to mention in particular silicon compounds, inparticular inorganic silicon compounds, such as silica, maleicanhydride, carbon black and fluorine or fluorinated hydrocarbons.Pigments, such as TiO₂, are optionally also present. The most suitableamounts of such additives can be readily determined by routineexperiments, and each additive which is present is preferably present inan amount of 0.05 to 3% by weight, more preferably of 0.1 to 2% byweight. Copolymer blends according to the invention which contain alubricant, a nucleating agent, a silicon compound and maleic anhydrideare particularly preferred.

If the ski is intended for high-performance applications, for exampleracing, it is possible to apply in a customary manner specialimpregnations which can preferably bind to polypropylene and whichimprove the hydrophobic and antistatic properties in the short term andwhich additionally increase the surface hardness. A mixture offluorinated isopropanol and water may be mentioned here.

It has surprisingly been found that a special blend of differentcopolymers as defined above can be processed by a simple extrusionprocess to give a sheet which is suitable in a particularly outstandingmanner as a sliding coating for winter sports equipment and inparticular for skis and snowboards. The coating changes its hardness ina temperature range from +20 to −20° C. so that it becomes harder withdecreasing temperature, an effect which could be achieved to date onlywith the use of waxes.

The sliding coatings according to the invention moreover have excellentnotched impact strength and strength which is comparable with that ofsliding coatings based on polyethylene, at least with regard to therequirements which winter sports equipment has to meet.

The copolymer blends for the production of the sliding coating accordingto the invention can be processed in a customary manner. A particularadvantage of the copolymer blends is that they can be formed intosliding coatings by customary extrusion processes, for example by filmextrusion processes. The press sintering processes required in the caseof other polymers, such as UHMW-PE, are not necessary according to theinvention. The processing can, according to the invention, therefore beeffected in customary single-screw and twin-screw extruders, inparticular in three-zone screw extruders having a mixing section,preferably in intermeshing three-zone twin-screw extruders having amixing section.

The extrusion dies are known to the person skilled in the art, andcustomary beam or coat hanger dies may be mentioned here as examples.For sizing, it is possible to use customary calender or smoothing rollunits, in particular so-called chill-roll units.

It is also advantageous according to the invention to apply to thesliding coating a surface structure which results in wettability whichis as low as possible. Surprisingly, it was found that, in the case ofthe sliding coating according to the invention to which a surfacestructure was applied in a customary manner, the wettability isparticularly greatly reduced so that a lotus effect occurs even withoutthe use of a wax.

A further advantage according to the invention arises from the fact thatpolypropylene has a so-called “memory effect” which occurs if thesurface structure is applied below the molecular transition point. As aresult of the memory effect, the surface structure is automaticallyrestored if it was slightly damaged by mechanical effects.

The surface structure is applied to the sliding coating in the same wayas that known in the case of skis, for example by using structuredsmoothing rolls. As mentioned above, it is preferable if the surfacestructure is applied to the sliding coating before the moleculartransition point.

The sliding coating according to the invention has, as a rule, athickness of 0.1 to 10 mm, preferably of 0.5 to 5 mm, in particular ofabout 1 mm.

The sliding coating according to the invention can be applied in acustomary manner to winter sports equipment, in particular skis orsnowboards. It is particularly preferable here to apply the slidingcoating to the winter sports equipment using suitable adhesives, forexample the customary hotmelt adhesives, or using a hotmelt plastic,such as, for example, a polyamide resin or an ethylene/vinyl acetatecopolymer or modifications thereof. However, the sliding coating canalso be bonded to the equipment in another known manner. Before theapplication, the winter sports equipment, in particular the ski or thesnowboard, can be subjected to a customary pretreatment, such asbrushing, sand-blasting, degreasing, etching or pickling, and thesliding coating can be subjected to a customary surface treatment, suchas, for example, a corona treatment, flame treatment, primer treatmentor ozone shower.

The following example explains the invention.

EXAMPLE

Mixture I:

8000 g of Exxon Mobil PP 7011L1, 2000 g of Dexplastomer Exact 0203, 100g of Hecoslip 103 PO (lubricant) and 160 g of Heconuk 484 PP.

Mixture II:

8000 g of Exxon Mobil PP 7011L1, 2000 g of Dexplastomer Exact 0203, 100g of Hecoslip 103 PO and 160 g of Heconuk 484 PP, and 100 g of ExxonMobil Exxelor PO 1020 (maleic anhydride) and 40 g of technical-gradesilicon powder (SiO₂).

Mixture III:

3500 g of Exxon Mobil PP 7011L1, 1500 g of Dexplastomer Exact 0203, 100g of Hecoslip 114 PP and 50 g of Hecoslip 103 PO.

The mixtures were each mixed for 30 minutes in a customary mixer. Themixture was then extruded in a film extrusion unit comprising athree-zone single-screw extruder of the Colin brand, having a chill-rollunit with smoothing roll, to give a 1 mm thick sheet. The surfacetreatment was effected using a customary ski stone grinding unit of theMontana brand.

Thereafter, small sample plates (5 cm×5 cm) per mixture were ground withabrasive paper having a particle size of about 8 μm and a grinding pastehaving a particle size of about 100 nm, with the result that a lotuseffect was imparted to the surface of the sliding coating. After thegrinding residues had been washed out, an extremely low-friction sheetsurface was obtained, on which water drops rolled away in sphericalform.

A considerable increase in the surface hardness was found on cooling thesheet, and a decrease in the surface hardness on heating.

The sheet comprising the mixtures I and II was applied to a ski and to asnowboard by using a customary adhesive in a known manner. This wintersport equipment was then tested on wet snow, cold and dry snow andartificial snow in order to carry out a qualitative sliding test inpractice. Skis and snowboards which had been equipped with thehighest-quality commercially available UHMW-PE sinter coatings of theP-TEX brand served as a reference. The reference coatings were providedon the same above-mentioned stone grinding unit with the same grindingpattern as those to be tested and were prepared professionally, as iscustomary for use in racing, with suitable waxes for the respective snowtemperature.

In comparison, the winter sports equipment with the novel coatingsaccording to the invention appeared to be in no way inferior to theconventional equipment. On the contrary, particularly on wet snow, themixture II appeared to be substantially superior, and the mixture Islightly superior, to the sinter coatings.

Below, the coatings according to the invention which are described aboveare designated as FX SmartBase, the mixture I being designated as FXSmartBase Basic and the mixture II as FX SmartBase Si type.

Quantitative analysis was effected using the following test setup, whichpermits an objective comparison of the sliding properties of the novelFX SmartBase coatings according to the invention with waxed referencecoatings. The setup is shown in FIG. 1.

A sled having the coating to be tested as a running surface is intendedto slide down a sloping plane of defined angle of inclination a andcomprising snow. The sled is initially held by a magnet. When thisdisengages, the timing begins and the sled passes through three lightbarriers (L1, L2, L3).

Here, the first time t1 is recorded over the first distance x1 (5.5 cm)from the magnet to L1. The second time t2 is then recorded over thesecond distance x2 (50 cm) to the light barrier L2, and finally thethird time t3 is recorded over the third distance x3 (50 cm) to thelight barrier L3.

A CPU from Jetter, model nano b, was used for control.

The magnet was an electromagnet from IBS with 24 V input voltage. IRlight barriers from IDEC, having a range of 80 cm and a reaction time of1 ms, were chosen as light barriers.

Coating samples having an area of 80 cm² of the FX SmartBase Basic andthe FX SmartBase Si type were compared on warm and cold snow with thereference coating P-Tex, which was prepared with suitable wax inrelation to the respective snow conditions.

All samples were provided with the same all round structure as shown inFIG. 2 on a stone grinding machine from Montana by the Crystal GlideFinish process.

For the warm and wet snow tests, the wax Eclipse EC1 High Fluorine +80to −3° C. from Star SkiWax was used at a snow temperature of −2° C. andan air temperature of +1.5° C.

For the cold and dry snow tests, the wax Eclipse EC2 High Fluorine 0° to−10° C. from Star Skiwax was used at a snow temperature of −6° C. and anair temperature of −4° C.

The wax was applied to the P-Tex samples using a wax iron from TOKO. Thesamples were then cooled at room temperature for two hours. The wax wasthen peeled off using a scraper from TOKO. The ground structure was thenbrushed out again using a structure brush from TOKO.

The FX SmartBase coatings were not waxed.

The coatings were mounted on the sled using double-sided adhesive tapeand screw connections.

The sled with the mounted coating was then weighed. The weigher used wasa precision weigher from Soehnle, model 8048 cyber which was accurate toa gram.

The tray, on the bottom of which lay an artificial lawn for betteradhesion of the snow, was then filled with snow, over which a straightedge was drawn so that a planar surface formed. Before each run, snowwas again poured onto the test piste and levelled off.

The sled was then mounted on the guide and led to the magnet withoutcontact with the bottom.

The magnet was switched off and the measurements at the light barrierswere carried out. Ten runs were carried out per coating, and theresulting times of all ten runs were averaged.

Thereafter, the averaged times were compared with one another and theaverage velocities were calculated.

Results:

All sleds with mounted coatings had the same weight, which was 339 g.The angle of inclination α was 15° in all tests, which corresponds to agradient of 25.88%.

1. Test series with warm and wet snow (snow temperature: −2° C., airtemperature: +1.5° C.) Measurement t [sec/100] x [cm] FX SmartBase BasicMean value L1 34.6 5.5 Mean value L2 95.4 55.5 Mean value L3 128.8 105.5FX SmartBase Si type Mean value L1 27.3 5.5 Mean value L2 82.3 55.5 Meanvalue L3 114.6 105.5 P-Tex + EC1 Mean value L1 40.2 5.5 Mean value L2102.4 55.5 Mean value L3 137.7 105.5Velocity: v=x/t

where:

v: Mean velocity

x: Distance

t: Time required for x gives:

FX SmartBase Si type: v=0.9206 m/s

FX SmartBase Basic: v=0.8190 m/s

P-Tex+EC1: v=0.7661 m/s

Thus, over a travel distance of 105.5 cm, the FX SmartBase Basic is6.90% faster and the FX SmartBase Si type 20.16% faster in the case ofthe wet snow tested. The result is shown in FIG. 3.

2. Test series with cold and dry snow (snow temperature: −6° C., airtemperature: −4° C.) Measurement t [sec/100] x [cm] FX SmartBase BasicMean value L1 27.5 5.5 Mean value L2 86.1 55.5 Mean value L3 124.4 105.5FX SmartBase Si type Mean value L1 27.2 5.5 Mean value L2 83.6 55.5 Meanvalue L3 119.7 105.5 P-Tex + EC2 Mean value L1 27.2 5.5 Mean value L287.2 55.5 Mean value L3 128 105.5Velocity: v=x/t

where:

v: Mean velocity

x: Distance

t: Time required for x gives:

FX SmartBase Si type: v=0.8813 m/s

FX SmartBase Basic: v=0.8480 m/s

P-Tex+EC2: v=0.8242 m/s

Thus, over a travel distance of 105.5 cm, the FX SmartBase Basic is2.88% faster and the FX SmartBase Si type 6.93% faster in the case ofthe cold snow tested. The result is shown in FIG. 4.

1. An article of winter sports equipment having a sliding coatingadhesively bonded thereto, said sliding coating comprising a blend of acopolymer (I) and a copolymer (II), the copolymer (I) being a copolymerof propylene and at least one first olefin, wherein said copolymer (I)contains at least 50% of structural building blocks which originate frompropylene monomer, based on the total number of structural buildingblocks, and the copolymer (II) being a copolymer of ethylene and atleast one second olefin, wherein said copolymer (II) comprises 70 to 99%of structural building blocks which originate from ethylene and 1 to 30%of structural building blocks which originate from said second olefin,based on the total number of structural building blocks.
 2. The articleof winter sports equipment of claimed in claim 1, wherein the copolymer(I) is present in an amount of 10 to 90% by weight and the copolymer(II) in an amount of 10 to 90% by weight, based in each case on thetotal weight of copolymer (I) and copolymer (II).
 3. The article ofwinter sports equipment of claim 1, wherein the blend furthermorecomprises a lubricant.
 4. The article of winter sports equipment ofclaimed in claim 3, wherein the lubricant is contained in an amount of0.5 to 30% by weight, based on the total weight of copolymer (I) andcopolymer (II).
 5. The article of winter sports equipment of claimed inclaim 3, wherein the lubricant is selected from the group consisting ofa primary or secondary fatty acid stable at high temperatures, acarboxylic ester and mixtures thereof.
 6. The article of winter sportsequipment of claimed in claim 1, wherein the blend furthermore comprisesa nucleating agent.
 7. The article of winter sports equipment of claimedin claim 1, wherein the blend also contains one or more furtheradditives selected from the group consisting of antistatic additives,additives for improving the hydrophobic properties, additives forimproving the resistance to weathering, additives for improving thescratch resistance and pigments.
 8. The article of winter sportsequipment of claimed in claim 7, wherein the blend contains a siliconcompound and/or maleic anhydride.
 9. The article of winter sportsequipment of claim 1, wherein the copolymer (I) is a propylene/ethylenecopolymer comprising at least 50% of structural building blocks whichoriginate from propylene monomer or an EPDM terpolymer comprising atleast 50% of structural building blocks which originate from propylenemonomer, based in each case on the total number of structural buildingblocks.
 10. The article of winter sports equipment of claim 9, whereinthe copolymer (I) is a propylene/ethylene copolymer comprising 70 to 99%of structural building blocks which originate from propylene monomersand comprising 1 to 30% of structural building blocks which originatefrom ethylene monomers, based in each case on the total number ofstructural building blocks.
 11. The article of winter sports equipmentof claim 1, wherein the copolymer (II) is a copolymer of ethylene and ahigher olefin having 4 to 10 carbon atoms or a terpolymer of ethylene,an olefin having 4 to 10 carbon atoms and a diene.
 12. The article ofwinter sports equipment of claim 11, wherein the olefin having 4 to 10carbon atoms is octene.
 13. The article of winter sports equipment ofclaim 1, which has a surface structure which was applied before themelting point.
 14. A process for the production of a sliding coating foran article of winter sports equipment as claimed in claim 1, wherein theblend of copolymer (I) and copolymer (II) is extruded by a filmextrusion process to give a sheet, to which optionally a surfacestructure is then applied before the melting point.
 15. The article ofwinter sports equipment of claim 1, wherein said article is a ski or asnowboard.
 16. The article of winter sports equipment of claim 1,wherein the copolymer (I) comprises 60 to 80% by weight of the blend andthe copolymer (II) comprises 20 to 40% by weight of the blend.
 17. Thearticle of winter sports equipment of claim 1, wherein the copolymer (I)comprises 70 to 80% by weight of the blend and the copolymer (II)comprises 20 to 30% by weight of the blend.